An ink-jet head comprises a substrate and a piezoelectric member mounted on the substrate. The piezoelectric member comprises a plurality of groove-like pressure chambers to be supplied with ink. Electrodes are disposed in the pressure chambers, individually, and are connected individually to a plurality of electrical traces on the substrate. A driver IC for controlling the ink-jet head is connected to the electrical traces. If the driver IC applies voltage to the electrodes in the pressure chambers through the electrical traces, the piezoelectric member undergoes a shear-mode deformation such that the ink in the pressure chambers can be discharged.
To prevent corrosion of electrically conductive portions or a short circuit, an insulating film is formed on the electrodes in the pressure chambers and the electrical traces on the substrate. In forming the insulating film, those portions to which the driver IC is connected are masked with, for example, grease.
After the insulating film is formed, that part of it located on the grease is removed. The driver IC is connected to the electrical traces exposed by the masking. On the other hand, the electrical traces are left exposed between the driver IC and an end portion of the insulating film. Thus, exposed parts of the electrical traces may be degraded.